Economy Aeration-Oxidation Free SO2 Test Kit
Measure free SO2 with the aeration-oxidation method
The Economy Aeration-Oxidation Free SO2 Test Kit gives home and small-scale winemakers a reusable, lab-style way to measure free sulfur dioxide in wine. It includes the glassware, air pump, tubing, pipettes, syringe, and starter reagents needed to run the test. The supplied reagents are enough for approximately two to three tests; the apparatus can be cleaned and reused with fresh reagents.
Free SO2 is the portion of sulfur dioxide available to help protect wine from oxidation and unwanted microbial activity. Measuring it gives you better information for sulfur additions than relying on an addition schedule alone. Accurate results still depend on careful sample measurement, tight tubing connections, fresh reagents, and a clearly observed titration endpoint.
How the test works
- A measured wine sample is acidified in the first flask.
- The pump moves the released sulfur dioxide into a second flask containing hydrogen peroxide and indicator.
- The trapped SO2 is converted to sulfuric acid, changing the indicator color.
- The receiving solution is titrated back to its starting endpoint with the supplied 0.01N sodium hydroxide.
- Free SO2 is calculated in parts per million: milliliters of 0.01N sodium hydroxide used multiplied by 16.
The pump portion of a test normally runs for 10 to 15 minutes, plus setup and titration time. The calculation above is specific to 0.01N sodium hydroxide. Do not substitute 0.1N sodium hydroxide and use the same formula.
What is included
- Two 125 mL flasks
- Two two-hole #5 stoppers
- Three-piece glass tubing set
- Silicone tubing and clear tubing
- Aspiration pump with 1/4-inch flow regulator
- Two quick disconnects
- Pipette bulb
- 10 mL syringe
- 10 mL and 20 mL pipettes
- Starter quantities of 3% hydrogen peroxide, 25% phosphoric acid, 0.01N sodium hydroxide, 0.01N hydrochloric acid, and SO2 indicator
What else you need
Have distilled water, a clean work area, eye protection, chemical-resistant gloves, a waste container, and baking soda available before testing. Follow the included instructions for assembly, endpoint adjustment, testing, cleaning, storage, and disposal. For a compatible acid refill, see our 25% phosphoric acid solution.
Reagent care and safe handling
Keep the hydrogen peroxide and sodium hydroxide tightly sealed and refrigerated, then allow them to reach room temperature before use. As a practical guideline, replace opened hydrogen peroxide after about two to three months and opened sodium hydroxide after about three to four months. Label every reagent, keep chemicals away from food and children, and wear eye protection and gloves while working.
The spent wine sample still contains phosphoric acid. Neutralize it with baking soda as directed before disposal. Always follow the kit instructions and applicable local disposal requirements.
Aeration-oxidation kit or Titrets?
Choose this kit when you want a reusable apparatus and are comfortable measuring samples and performing a titration. For a more compact, single-use option, compare the Titrets Free SO2 Tester. Each method has its own procedure and limitations, so use the instructions supplied with the product you select.
Frequently asked questions
Does this kit measure free or total SO2?
This kit is configured to measure free SO2.
How many tests are included?
The starter reagents support approximately two to three tests. The pump, tubing, glassware, pipettes, and syringe are reusable.
How long does one test take?
Allow 10 to 15 minutes for the pump run, plus time to prepare the sample, adjust the endpoint, titrate, calculate the result, and clean the equipment.
Can I use 0.1N sodium hydroxide?
No. The stated calculation—milliliters used multiplied by 16—requires 0.01N sodium hydroxide.